Select > Stereo Settings > Audio Zones, and if necessary, select a zone.
Zone Name: Sets the name of the zone.
Loud: Boosts the high and low frequencies.
Subwoofer Filter: Sets the low-pass frequency of the subwoofer.
Bass: Sets the relative volume of low-frequency audio.
Middle: Sets the relative volume of middle-frequency audio.
Treble: Sets the relative volume of high-frequency audio.